Oil pan design for drawing two sumps from a single drain plug

ABSTRACT

Oil pan assemblies and methods of draining oil pans are disclosed. An example oil pan assembly includes an oil pan defining first and second sumps. The first sump has a first lower surface and the second sump has a second lower surface. The second lower surface is elevated along a vertical axis relative to the first lower surface. The oil pan assembly also includes a siphon tube extending from an inlet positioned in the second sump to an outlet positioned proximate a drain hole in the first sump. The siphon tube is configured to automatically transmit oil from the second sump to the first sump upon oil being drained from the drain hole.

TECHNICAL FIELD

The present disclosure relates generally to oil pan assemblies andmethods of draining oil pans.

BACKGROUND

Oil is used to lubricate the moving parts of an internal combustionengine. Oil moves from its reservoir, is pressurized by an oil pump, andis pumped through an oil filter to remove contaminants. The oil is thenprovided to the crankshaft and connecting rod bearings and onto thecylinder walls. Eventually, the oil drips off into the bottom of thecrankcase. In a wet sump system, oil remains in a reservoir at thebottom of the crankcase. The bottom of the crankcase is often referredto as an oil pan. In a dry sump system, the oil is instead pumped to anexternal reservoir.

Conventionally, oil pans have included a single sump (e.g., reservoir).However, modern engine systems have become increasingly complicated overtime, with more components being fit into tighter spaces. Therefore, insome arrangements, oil pans include complex geometry in order to fit ina constrained space proximate other vehicle components (e.g., structuralcross-members, tie rods, steering racks, etc.). For example, some oilpans include two sumps. However, in certain arrangements, it may bedifficult for technicians or users to properly drain oil from each ofthe two sumps.

SUMMARY

Various embodiments relate to an oil pan assembly including an oil pandefining first and second sumps. The first sump has a first lowersurface and the second sump has a second lower surface. The second lowersurface is elevated along a vertical axis relative to the first lowersurface. The oil pan assembly also includes a siphon tube extending froman inlet positioned in the second sump to an outlet positioned proximatea drain hole in the first sump. The siphon tube is configured toautomatically transmit oil from the second sump to the first sump uponoil being drained from the drain hole.

Further embodiments relate to an oil pan assembly including an oil pandefining first and second sumps. The first sump has first lower surfaceand the second sump has a second lower surface. The second lower surfaceis elevated along a vertical axis relative to the first lower surface.The oil pan assembly also includes a suction tube positioned within thefirst sump. The oil pan assembly further includes a siphon tube thatincludes a first segment positioned within the first sump, a secondsegment positioned within the second sump, and a third segment fluidlycoupling the first and second segments. Further yet, the oil panassembly includes a crossover tube fluidly coupling the suction tube andthe siphon tube. Still further, the oil pan assembly includes an oilpump operatively coupled to the suction tube. The oil pump is configuredto cause a pressure differential within each of the suction tube and thesiphon tube to draw a fluid through each of the suction tube and thesiphon tube.

Further embodiments relate to a method for draining oil from an oil panhaving first and second sumps. The method includes removing a drain plugfrom a drain hole in the first sump. The method also includes collectingoil that is drained from the drain hole. The method further includescausing a pressure imbalance within a siphon tube so as to cause oilwithin the second sump to pass through the siphon tube and into thefirst sump.

This summary is provided to introduce a selection of concepts that arefurther described below in the illustrative embodiments. This summary isnot intended to identify key or essential features of the claimedsubject matter, nor is it intended to be used as an aid in limiting thescope of the claimed subject matter. Further embodiments, forms,objects, features, advantages, aspects, and benefits shall becomeapparent from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-section of a conventional dual sump oil pan assembly.

FIG. 2A-2B are cross-sectional views of a dual sump oil pan assembly inwhich both sumps may be drained from a single drain hole, according toan example embodiment.

FIG. 3A illustrates a siphon tube for use with a dual sump oil panaccording to another example embodiment.

FIG. 3B illustrates a siphon tube for use with a dual sump oil panaccording to still another example embodiment.

FIG. 4A is a cross-sectional view of a dual sump oil pan assemblyaccording to an example embodiment.

FIG. 4B illustrates an alternative embodiment of the dual sump oil panassembly of FIG. 4A.

FIG. 5 is a flow diagram of a method of draining oil from an oil panhaving first and second sumps, according to an example embodiment.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated embodiments, and that such furtherapplications of the principles of the invention as illustrated thereinas would normally occur to one skilled in the art to which the inventionrelates are contemplated and protected.

The present disclosure relates to a dual sump oil pan assembly that iscapable of draining both sumps from a single drain hole. In particular,the oil pan assembly includes a self-priming siphon tube thatautomatically transmits oil from the second sump to the first sump whenthe oil is drained, such that both sumps may be drained from a singledrain hole in the first sump.

FIG. 1 is a cross-sectional view of a conventional dual sump oil panassembly 100. The oil pan assembly 100 includes an oil pan 102 having aflange 104 to mount the oil pan 102 to a crank case of an engine (notshown). The oil pan 102 is shaped so as to define a first sump 106 and asecond sump 108, which are separated by a raised portion 110. Inoperation, oil collects in the first and second sumps 106, 108 afterlubricating engine components.

The oil pan 102 defines a first drain hole 112 at the bottom of thefirst sump 106 and defines a second drain hole 114 at the bottom of thesecond sump 108. Each of the first and second drain holes 112, 114include respective threaded inserts 116, 118 to accept drain plugs (notshown). To change the oil, the drain plugs are removed, and oil withineach of the first and second sumps 106, 108 drains from the oil panassembly 100 through the corresponding first and second drain holes 112,114.

For various reasons, technicians and users are more likely to conductoil changes improperly with oil pans having multiple drain plugs thanwith those having a single drain plug. Because technicians and users aretypically used to working with oil pans having a single drain plug, theymay forget or may simply not know to remove each drain plug. If eachsump is not drained, the spent oil remaining in the un-drained sump willmix with fresh oil, thereby reducing the useful life of the oil andreducing the interval time until the next oil change is required.Further, because other vehicle components are likely to be arranged inclose proximity to the oil pan assembly 102, it may be difficult for atechnician or operator to access one of the drain plugs. In fact, closeproximity of other vehicle components is one of the reasons why certainoil pans have multiple sumps. Therefore, one of the drainplugs—typically the drain plug of the second drain hole 114—may bedifficult to access. Therefore, it may be difficult to locate, remove,and/or properly tighten the drain plug of the second drain hole 114.Thus, it is desirable to provide a system in which both sumps of a dualsump oil pan can be drained from a single drain hole.

FIG. 2A is a cross-sectional view of a dual sump oil pan assembly 200 inwhich both sumps may be drained from a single drain hole, according toan example embodiment. The oil pan assembly 200 is shown in FIG. 2A inan at-rest orientation. In other words, the oil pan assembly 200 isshown in an orientation as if it was mounted to a crankcase of an enginewithin a vehicle disposed on a flat surface. The oil pan assembly 200includes an oil pan 202 having a flange 204. Similar to the oil panassembly 100 of FIG. 1, the oil pan 202 is shaped so as to define afirst sump 206 and a second sump 208, which are separated by a raisedportion 210. The raised portion 210 serves as a barrier to prevent oilfrom passing from one of the first and second sumps 206, 208 to theother of the first and second sumps 206, 208. The first sump 206includes a first lower surface 209, and the second sump 208 includes asecond lower surface 211. The second lower surface 211 is elevated alonga vertical axis 213 relative to the first lower surface 209. In otherwords, the first sump 206 is deeper than the second sump 208. Inoperation, oil collects in the first and second sumps 206, 208 afterlubricating engine components. The oil pan 202 also defines a drain hole212 on the first lower surface 209 of the first sump 206. The drain hole212 includes a threaded insert 214 to accept a drain plug (not shown).Notably, the oil pan 202 consists of a single drain hole 212.

The oil pan assembly 200 also includes a siphon tube 216 disposed withinthe oil pan 202. The siphon tube 216 has a first segment 218 positionedin the first sump 206. The first segment 218 defines an outlet 220positioned proximate the drain hole 212 in the first sump 206. Thesiphon tube 216 also has a second segment 222 positioned in the secondsump 208. The second segment 222 defines an inlet 224 positionedproximate the second lower surface 211 of the second sump 208. A thirdsegment 228 extends over the raised portion 210, fluidly coupling thefirst segment 218 and the second segment 222.

According to an example embodiment, the siphon tube 216 is formed bybending a unitary tube (e.g., ¼″-½″ or larger steel or aluminum tubing)at a first point 227 defining an interface between the first segment 218and the third segment 228, and at a second point 229 defining aninterface between the second segment 222 and the third segment 228. Insome examples, the siphon tube 216 is bent or otherwise formed such thateach of the first and second segments 218, 222 are positioned atnon-zero angles relative to the vertical axis 213. According to onenon-limiting example, the first segment 218 is angled at about 45degrees relative to the vertical axis 213 and the second segment 222 isangled at approximately 30 degrees relative to the vertical axis. Asshown in FIG. 2A, for example, the first segment 218 is angled such thatthe outlet 220 is positioned proximate the drain hole 212. The secondsegment 222 is also angled such that the inlet 224 clears a radius 234of the oil pan 202, thereby positioning the inlet 224 over a flatportion of the second lower surface 211.

In some arrangements, the outlet 220 of the first segment 218 is cut orshaped at an angle such that the outlet 220 is substantially parallelwith the first lower surface 209 of the first sump 206. Similarly, insome arrangements, the inlet 224 of the second segment 222 is cut orshaped at an angle, such that the inlet 224 is substantially parallelwith the second lower surface 211 of the second sump 208. By angling thefirst segment 218 and the outlet 220, the height differential betweenthe outlet 220 and the oil level in the second sump 208 is maximized,thereby maximizing the pressure along the streamline of the siphon tube216. Further, by angling the second segment 222 and the inlet 224, themaximum amount of oil may be removed from the second sump 208.

The siphon tube 216 provides fluid communication between the second sump208 and the first sump 206. In particular, the siphon tube 216 isconfigured to transmit oil within the second sump 208 into the inlet 224of the siphon tube 216; through the second segment 222, the thirdsegment 228, and the first segment 218 of the siphon tube 216; and outof the outlet 220 of the siphon tube 216 and into the first sump 206,such that the oil may ultimately be drained from the oil pan 202 throughthe drain hole 212. As discussed in further detail below in connectionwith FIG. 2B, the siphon tube 216 is “self-priming” such that oil isautomatically transmitted through the siphon tube 216 from the secondsump 208 to the first sump 206 upon oil being drained from the firstsump 206.

The siphon tube 216 may be attached to the oil pan 202 in various ways.In some arrangements, the third segment 228 of the siphon tube 216 isattached to the raised portion 210 of the oil pan 202 via one or morecouplings 230. In one arrangement, the couplings 230 include welds suchthat the siphon tube 216 is fixedly coupled to the oil pan 202. Inanother arrangement, the couplings 230 include removable fasteners(e.g., hose clamps or other fasteners) such that the siphon tube 216 isremovably coupled to the oil pan 202.

FIG. 2B is another cross-sectional view of the dual sump oil panassembly 200 of FIG. 2A. As shown in FIG. 2B, oil within the first sump206 has a first oil level 236 and oil within the second sump 208 has asecond oil level 238. In some arrangements, the first and second oillevels 236, 238 are the same during steady-state conditions (e.g., whenoil is not being drained from the oil pan 202). In some arrangements,the first and second oil levels 236, 238 are above the third segment 228of the siphon tube 216 during steady-state conditions. In otherarrangements, the first and second oil levels 236, 238 are differentduring steady-state conditions. A first height differential 240 extendsbetween the second oil level 238 and the outlet 220. A second heightdifferential 242 extends between the second oil level 238 and acenterline of the third segment 228 of the siphon tube 216.

During steady-state conditions (e.g., when oil is not being drained fromthe oil pan 202), the oil within the first sump 206 fills the firstsegment 218 of the siphon tube 216 up to the first oil level 236.Similarly, oil within the second sump 208 fills the second segment 222of the siphon tube 216 up to the second oil level 238. When the oil isbeing drained from the drain hole 212 of the oil pan 202, the siphontube 216 operates as a siphon such that the oil flowing out of the firstsegment 218 due to gravity reduces the pressure in the third segment228. The reduced pressure in the third segment 228 causes the oil withinthe second segment 222 to flow upwards into the third segment 228,through the third segment 228 into the first segment 218, and from theoutlet 220 of the first segment 218 into the first sump 206, eventuallyexiting the oil pan 202 through the drain hole 212. Oil within thesecond sump 208 continuously flows through the second segment 222, thethird segment 228, and the first segment 218 until the second oil level238 falls below the inlet 224.

FIG. 3A illustrates a siphon tube 302 for a dual sump oil pan 304according to another example embodiment. The siphon tube 302 of FIG. 3Ais similar to the siphon tube 216 of FIGS. 2A and 2B. However, thesiphon tube 302 of FIG. 3A has first and second segments 306, 308 thatare substantially parallel with a vertical axis 310. In contrast, thefirst and second segments 218, 222 of the siphon tube 216 of FIG. 2A areangled at non-zero angles relative to the vertical axis 213.

The first segment 306 is connected, at a first end thereof, to a firstend of a third segment 312. Similarly, the second segment 308 is coupledat a first end thereof to a second end of the third segment 312. Thesiphon tube 302 of FIG. 3 also has a fourth segment 314 extendingsubstantially perpendicularly from a second end of the first segment306. Furthermore, a fifth segment 316 extends substantiallyperpendicularly from a second end of the second segment 308. The fourthsegment 314 defines an outlet 318, and the fifth segment 316 defines aninlet 320. In some arrangements, the outlet 318 is cut or shaped at anangle so as to discharge oil towards a drain hole 322 in the oil pan304.

FIG. 3B illustrates a siphon tube 324 for a dual sump oil pan 304according to still another example embodiment. The siphon tube 324 is analternative embodiment of the siphon tube 302 of FIG. 3A. The siphontube 324 of FIG. 3B is similar to the siphon tube 302 of FIG. 3A, exceptthat an outlet 326 of a fourth segment 328 of the siphon tube 324includes drainage holes 330 proximate the drain hole 322 of the oil pan304, as opposed to the outlet 318 of the siphon tube 302 of FIG. 3Abeing cut as an angle. In one example, the drainage holes 330 have acombined surface area that is approximately equal to an innercross-sectional surface area of the siphon tube 324. Further, an end 332of the fourth segment 328 may be open or enclosed, according to variousembodiments.

FIG. 4A is a cross-sectional view of a dual sump oil pan assembly 400 inwhich both sumps may be drained from a single drain hole, according toanother example embodiment. The oil pan assembly 400 includes an oil pan402 that is configured to be mounted to a crankcase of an engine. Theoil pan 402 is generally similar in shape as the oil pan 202 of FIGS.2A-2B. For example, the oil pan 402 is shaped so as to define a firstsump 404 and a second sump 406, which are separated by a raised portion408. The first sump 404 includes a first lower surface 410, and thesecond sump 406 includes a second lower surface 412. The second lowersurface 412 is elevated along a vertical axis 414 relative to the firstlower surface 410. The oil pan 402 also defines a drain hole 416 on thefirst lower surface 410 of the first sump 404. The drain hole 416includes a threaded insert 418 to accept a drain plug (not shown).Notably, the oil pan 402 consists of a single drain hole 416.

The oil pan assembly 400 also includes a suction tube 420 disposed atleast partially within the first sump 404. The suction tube 420 includesa pickup portion 422 and a transfer portion 424. The transfer portion424 is operatively coupled to an oil pump 426. The oil pump 426 isconfigured to cause a pressure differential within the suction tube 420to draw oil from the first sump 404 to various components of the engine.In various implementations, the oil pump 426 draws oil through an oilfilter and sometimes an oil cooler, before the oil is transferredthrough the engine's oil passages and is dispersed to lubricate variousengine components, such as pistons, rings, springs, valve stems, etc.

As illustrated in FIG. 4A, the pickup portion 422 is positionedsubstantially parallel to the first lower surface 410 of the first sump404. According to various embodiments, the pickup portion 422 includes asingle inlet 428 at the free end of the pickup portion. In otherembodiments, the pickup portion 422 includes multiple inlets positionedabout the length of the pickup portion 422. According to an embodiment,the position and configuration of the pickup portion 422 facilitates thetransfer of oil from the first sump 404 even if the level of oil withinthe first sump 404 is low.

The oil pan assembly 400 also includes a siphon tube 430 disposed withinthe oil pan 402. The siphon tube 430 has a first segment 432 positionedin the first sump 404. The first segment 432 defines an outlet 434. Thesiphon tube 430 also has a second segment 436 positioned in the secondsump 406. The second segment 436 defines an inlet 438 positionedproximate the second lower surface 412 of the second sump 406. A thirdsegment 440 extends over the raised portion 408, fluidly coupling thefirst segment 432 and the second segment 436.

The oil pan assembly 400 further includes a crossover tube 442 thatfluidly couples the suction tube 420 and the siphon tube 430. Morespecifically, as illustrated in FIG. 4A, the crossover tube 442 isfluidly coupled to each of the transfer portion 424 of the suction tube420 and to the first segment 432 of the siphon tube 430.

According to various embodiments, each of the suction tube 420, thesiphon tube 430, and the crossover tube 442 may be constructed ofvarious materials, such as bent metal (e.g., steel or aluminum) tubing,braided metal (e.g., steel) tubing, polymer (e.g., nitrile, chlorinatedpolyethylene (CPE), etc., which may be reinforced, for example, withHypalon®) tubing, and other types of tubing known to those havingordinary skill in the art. Each of the suction tube 420, the siphon tube430, and the crossover tube 442 may be constructed of the same ordifferent materials. For example, in one embodiment, each of the suctiontube 420 and the siphon tube are formed from steel tubing and thecrossover tube 442 is formed from polymer tubing. Further, each of theof the suction tube 420, the siphon tube 430, and the crossover tube 442may include various types of fittings as known to those having ordinaryskill in the art to facilitate the fluid couplings described above.

The oil pan assembly 400 of FIG. 4A, including the suction tube 420fluidly coupled to the siphon tube 430 via the crossover tube 442,facilitates improved oil transfer from the second sump 406 to the firstsump 404. In operation, the oil pump 426 causes a pressure differentialwithin the suction tube 420 to draw oil from the first sump 404 tovarious components of the engine. In doing so, a pressure differentialis also formed within the crossover tube 442, which is fluidly coupledto the suction tube 420. In turn, a pressure differential is furtherformed within the siphon tube 430, which is fluidly coupled to thecrossover tube 442. The pressure differential within the siphon tube 430causes fluids, such as air and oil, within the second and third segments436, 440 of the siphon tube 430 to be drawn to the first segment 432.Upon entering the first segment 432, the fluids may be discharged intothe first sump 404 through the outlet 434 of the first segment 432,and/or may be drawn through the crossover tube 442 and into the transferportion 424 of the suction tube 420. According to various embodiments,such fluid transfer, including the transfer of air pockets within thesiphon tube 430 operates to prime the siphon tube 430, thereby causingoil to flow through the siphon tube 430 from the second sump 406 to thefirst sump 404. Accordingly, oil within the second sump 406 that istransferred to the first sump 404 may be utilized to cool and lubricatethe engine, and may be easily drained through the single drain hole 416of the first sump 404.

FIG. 4B illustrates an alternative embodiment of the oil pan assembly400 of FIG. 4A. As illustrated in FIG. 4B, the first segment 432 of thesiphon tube 430 terminates into the crossover tube 442 (e.g., via anelbow fitting). Accordingly, in the embodiment illustrated in FIG. 4B,the first segment 432 of the siphon tube 430 does not include the outlet434 of FIG. 4A. Thus, in the embodiment of FIG. 4B, oil is drawn fromthe second sump 406 through the siphon tube 430, through the crossovertube 442, and into the transfer portion 404 of the suction tube 420.

FIG. 5 is a flow diagram of a method 500 for draining oil from an oilpan having first and second sumps, according to an example embodiment.For example, the method 500 may be performed using the oil pan assembly200 of FIGS. 2A and 2B, the oil pan assembly 300 of FIGS. 3A and 3B, orthe oil pan assembly 400 of FIGS. 4A and 4B. For purposes of clarity andbrevity, the method 500 is described below with respect to the oil panassembly 200 of FIGS. 2A and 2B. However, the method 500 is not limitedto this particular embodiment and may similarly be performed on otheroil pan assemblies.

At 502, a drain plug is removed from the drain hole 212 in the firstsump 206. Drain plugs are often threadedly coupled to drain holes andcan typically be removed using a wrench. Upon removing the drain plug at502, oil begins to flow from the drain hole 212. At 504, oil iscollected from the drain hole 212. For example, the oil may be collectedin a receptacle such as a drain pan.

At 506, a pressure imbalance is caused within the siphon tube 216 so asto cause oil within the second sump 208 to pass through the siphon tube216 into the first sump 206. In an embodiment, upon the drain plug beingremoved at 502, oil within the first segment 218 of the siphon tube 216flows out of the first segment 218 and causes the pressure imbalance,which includes a pressure reduction in the second segment 222 of thesiphon tube 216. In other embodiments, the oil pump 426 causes thepressure imbalance. The pressure reduction causes oil within the secondsegment 222 to flow from the second segment 222 through the thirdsegment 228 and into the first segment 218. The oil then flows out ofthe first segment 218, into the first sump 206, and through the drainhole 212. The oil within the second sump 208 continues to flow throughthe second segment 222, the third segment 228, and the first segment 218of the siphon tube 216 until a level of oil within the second sump 208falls below the inlet 224 of the siphon tube 216.

As utilized herein, the terms “approximately,” “about,” “substantially,”and similar terms are intended to have a broad meaning in harmony withthe common and accepted usage by those of ordinary skill in the art towhich the subject matter of this disclosure pertains. It should beunderstood by those of skill in the art who review this disclosure thatthese terms are intended to allow a description of certain featuresdescribed and claimed without restricting the scope of these features tothe precise numerical ranges provided. Accordingly, these terms shouldbe interpreted as indicating that insubstantial or inconsequentialmodifications or alterations of the subject matter described and claimedare considered to be within the scope of the invention as recited in theappended claims.

It should be noted that the terms “example” and “exemplary” as usedherein to describe various embodiments are intended to indicate thatsuch embodiments are possible examples, representations, and/orillustrations of possible embodiments (and such term is not intended toconnote that such embodiments are necessarily extraordinary orsuperlative examples).

It is important to note that the construction and arrangement of thevarious exemplary embodiments are illustrative only. Although only a fewembodiments have been described in detail in this disclosure, thoseskilled in the art who review this disclosure will readily appreciatethat many modifications are possible (e.g., variations in sizes,dimensions, structures, shapes and proportions of the various elements,values of parameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter described herein. Forexample, elements shown as integrally formed may be constructed ofmultiple parts or elements, the position of elements may be reversed orotherwise varied, and the nature or number of discrete elements orpositions may be altered or varied. The order or sequence of any processor method steps may be varied or re-sequenced according to alternativeembodiments. Other substitutions, modifications, changes and omissionsmay also be made in the design, operating conditions and arrangement ofthe various exemplary embodiments without departing from the scope ofthe present invention.

What is claimed is:
 1. An oil pan assembly, comprising: an oil pandefining first and second sumps, the first sump having a first lowersurface, the second sump having a second lower surface, the second lowersurface elevated along a vertical axis relative to the first lowersurface; and a siphon tube extending from an inlet positioned in thesecond sump to an outlet positioned proximate a drain hole in the firstsump, the siphon tube configured to automatically transmit oil from thesecond sump to the first sump upon oil being drained from the drainhole.
 2. The oil pan assembly of claim 1, wherein the siphon tube isconfigured to operate as a self-priming siphon to transmit oil from thesecond sump to the first sump.
 3. The oil pan assembly of claim 1,wherein the oil pan consists of a single drain hole.
 4. The oil panassembly of claim 1, wherein the siphon tube includes a first segmentpositioned in the first sump, a second segment positioned in the secondsump, and a third segment connecting the first and second segments, thethird segment extending over a raised portion of the oil pan between thefirst and second sumps, wherein the first segment defines the outlet andthe second segment defines the inlet.
 5. The oil pan assembly of claim4, wherein the siphon tube is configured such that, upon oil beingdrained from the drain hole, oil within the first segment flows out ofthe first segment and causes a pressure reduction in the second segment,the pressure reduction causing oil within the second segment to flowthrough the third segment and into the first segment, wherein oil withinthe second sump continues to flow through the second segment, the thirdsegment, and the first segment until a level of oil within the secondsump falls below the inlet.
 6. The oil pan assembly of claim 4, whereinthe first segment is positioned at a non-zero angle relative to thevertical axis.
 7. The oil pan assembly of claim 4, wherein the secondsegment is positioned at a non-zero angle relative to the vertical axis.8. The oil pan assembly of claim 4, wherein the third segment is weldedto the raised portion.
 9. The oil pan assembly of claim 1, wherein theoutlet is shaped at an angle such that the outlet is substantiallyparallel with the first lower surface.
 10. The oil pan assembly of claim1, wherein the inlet is shaped at an angle such that the inlet issubstantially parallel with the second lower surface.
 11. The oil panassembly of claim 1, wherein the siphon tube includes a first segmentpositioned in the first sump, a second segment positioned in the secondsump, a third segment connecting the first and second segments andextending over a raised portion of the oil pan between the first andsecond sumps, a fourth segment extending from the first segment withinthe first sump, and a fifth segment extending from the second segmentwithin the second sump, wherein the fourth segment defines the outletand the fifth segment defines the inlet.
 12. The oil pan assembly ofclaim 11, wherein the first and second segments are substantiallyparallel with the vertical axis, and wherein the fourth and fifthsegments are substantially perpendicular to the vertical axis.
 13. Theoil pan assembly of claim 12, wherein the outlet is shaped at an angleso as to discharge oil towards the drain hole.
 14. The oil pan assemblyof claim 12, wherein the outlet includes a plurality of drainage holespositioned above the drain hole.
 15. An oil pan assembly, comprising: anoil pan defining first and second sumps, the first sump having a firstlower surface, the second sump having a second lower surface, the secondlower surface elevated along a vertical axis relative to the first lowersurface; a suction tube positioned within the first sump; a siphon tubeincluding a first segment positioned within the first sump, a secondsegment positioned within the second sump, and a third segment fluidlycoupling the first and second segments; a crossover tube fluidlycoupling the suction tube and the siphon tube; and an oil pumpoperatively coupled to the suction tube, the oil pump configured tocause a pressure differential within each of the suction tube and thesiphon tube to draw a fluid through each of the suction tube and thesiphon tube.
 16. The oil pan assembly of claim 15, wherein the firstsegment of the siphon tube includes an outlet, and wherein the fluid tobe drawn through the siphon tube is to be discharged into the first sumpthrough the outlet.
 17. The oil pan assembly of claim 15, wherein thefluid to be drawn through the siphon tube is to be discharged into thesuction tube via the crossover tube.
 18. The oil pan assembly of claim15, wherein the first sump includes a drain hole, and wherein the oilpump is configured to transfer oil from within the second sump to thefirst sump to facilitate draining of the oil from the second sumpthrough the drain hole.
 19. A method for draining oil from an oil panhaving first and second sumps, comprising: removing a drain plug from adrain hole in the first sump; collecting oil that is drained from thedrain hole; and causing a pressure imbalance within a siphon tube so asto cause oil within the second sump to pass through the siphon tube andinto the first sump.
 20. The method of claim 19, wherein the causing ofthe pressure imbalance occurs automatically upon the removing of thedrain plug.
 21. The method of claim 19, wherein the first sump defines afirst lower surface and the second sump defines a second lower surface,the second lower surface elevated along a vertical axis relative to thefirst lower surface.
 22. The method of claim 19, wherein the siphon tubeincludes a first segment positioned in the first sump, a second segmentpositioned in the second sump, and a third segment connecting the firstand second segments, the third segment extending over a raised portionof the oil pan between the first and second sumps, wherein the firstsegment defines an outlet and the second segment defines an inlet. 23.The method of claim 22, wherein, the pressure imbalance includes apressure reduction in the second segment, the pressure reduction causingoil within the second segment to flow through the third segment and intothe first segment, wherein oil within the second sump continues to flowthrough the second segment, the third segment, and the first segmentuntil a level of oil within the second sump falls below the inlet. 24.The method of claim 19, wherein the oil pan consists of a single drainhole.